Making my first solera.

Construction and repair of Classical Guitar and related instruments
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sbooder
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Making my first solera.

Post by sbooder » Fri Mar 08, 2019 7:55 pm

Hi All,
Building my first solera this weekend. Would love any tips or crit on what I am about to do.

I am following the build in Making Master Guitars by Roy Courtnall. I am using 20mm MDF and not 18mm (it’s what I could get my hands on), but am following everything else pretty much to the letter.

I have my template for guitar body and I have made a circle out of particle board with the radius of 75mm to use like the washer trick to create the 75mm outer edge of the solera from the actual shape of the guitar. You may notice from the photo below that the circle is just a little too wide for the waist of the template? This however is a short distance of about 2” to do over by freehand. I will probably seal the edges of the MDF after cutting out the shape of the solera before I continue, just to protect the fragile edges.

I was thinking of drill and cutting the slots and holes on one side of the solera and then creating a half template out of cardboard just to transfer them to the other side so they are mirrored exactly.

I have not decided yet how I am going to create the dished portion of the solera, and am trying to avoid methods that involve router jigs!

So any tips most welcome.

Image
Kind regards,
Simon.

simonm
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Re: Making my first solera.

Post by simonm » Fri Mar 08, 2019 8:06 pm

The neck setting suggested in the Courtnall book is too much. Known issue. Do not slant it down 3mm. 1mm - 1.5mm is plenty. If you search here you will find it discussed on a number of occasions.

MDF dust is beastly. Get a really good dusk mask - the respirator type with a cartridge on each side. (25-35 euros) They are actually comfortable enough. The paper things are a total waste of money. You only get one pair of lungs.

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sbooder
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Re: Making my first solera.

Post by sbooder » Fri Mar 08, 2019 8:55 pm

simonm wrote:
Fri Mar 08, 2019 8:06 pm
The neck setting suggested in the Courtnall book is too much. Known issue. Do not slant it down 3mm. 1mm - 1.5mm is plenty. If you search here you will find it discussed on a number of occasions.

MDF dust is beastly. Get a really good dusk mask - the respirator type with a cartridge on each side. (25-35 euros) They are actually comfortable enough. The paper things are a total waste of money. You only get one pair of lungs.
Thanks for the tips Simon. I was wondering about the neck slant. I watch Pablo Requena's vids a lot and he slopes by 1.5mm (I think). And yes I will get a good mask.
Kind regards,
Simon.

vesa
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Re: Making my first solera.

Post by vesa » Sat Mar 09, 2019 6:32 am

Depends also on doming + other things.
My doming is 1.8 and slope 1.6.
That gives me about 11 string height with 6.5 thick fingerboard.
There is an equation about it by Les Backshall:
There are quite a few threads on the forum about neck angles and doming a solera which would repay reading - neck geometry is a subject that none of the standard books tackles well. Also, it has been pointed out here that the 3mm angle in Courtnall is a mistake (misprint?) and he actually uses 1mm.

Here's an equation which explains how the various elements interact.

SH=(FB+FR+(A*2))-(D+N)

SH = Saddle Height (12)
FB = Fingerboard thickness (6)
FR = Fret Height (1)
A = Action at F12 (3.5 @ E6)
D = Doming at bridge (2)
N = Neck Set (?)

If you punch in the numbers from Courtnall - (in brackets above), you will see that for the 12mm initial string height, the neck set would be zero. However, although you want a low action, which 3.5mm is, you might want to shoot for 4mm for some 'wriggle room' - so 1mm should be ok. Personally, I find that a 3mm dome and a dead flat neck works fine.


Les
Vesa Kuokkanen

Antonio Marin nr. 813 1995 (Bouchet)
Vesa Kuokkanen 2016

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sbooder
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Re: Making my first solera.

Post by sbooder » Sat Mar 09, 2019 8:05 am

vesa wrote:
Sat Mar 09, 2019 6:32 am
Depends also on doming + other things.
My doming is 1.8 and slope 1.6.
That gives me about 11 string height with 6.5 thick fingerboard.
There is an equation about it by Les Backshall:
Thanks Vesa, just when I thought I had a handle on this...it goes and gets all complicated again. Ho-hum! I am sure I will work it out, but I do have the sort of brain that melts at the sight of an equation.
Kind regards,
Simon.

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Mollbarre
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Re: Making my first solera.

Post by Mollbarre » Sat Mar 09, 2019 2:29 pm

Cool! Post lots of photos! I love watching the progress!
2016 Fender CN320AS
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wombosi
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Re: Making my first solera.

Post by wombosi » Sat Mar 09, 2019 2:38 pm

I made a solera from MDF. Some things I learned:

I had a real hard time keeping the mdf flat. Initially I glued a quartersawn piece of roughly 2X2" hard maple across the bottom length of it, which worked well in that plane. But the sides wound up warping a bit. I haven't actually used mine yet as I'm not in the assembly phase and will have to modify it or make another one to keep my side molds square. I'd probably redo it with a half-lapped cross brace structure underneath of something very rigid to keep the sides from warping.
Once you create the dish, seal the entire thing immediately with shellac or whatever.

I just used a card scraper to create the dome in the lower bout only. I made roughly a 2mm deep dish. You'll have to decide how much dome you want and where, but I would anticipate some springback after gluing the braces.

I did use my solera for gluing in my braces, with go-bars, but after a day or so the top completely cupped and did not retain the dome at all across it's width. I wound up putting it back in my back radius dish (15' radius), and wetted the top side a bit. This corrected it for a few days, but now it's screwy again. The point is, you should expect your top to move a great deal once it's at final thickness, and depending on your shop's climate, so don't get too hung up on the depth of your solera's dish. Then again maybe my case is not the norm. But I'm hoping my dome will be corrected upon assembly, with help from the sides and the bridge being contoured.

I have my neck ramp at 2mm built into the solera.

Good luck.

vesa
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Re: Making my first solera.

Post by vesa » Sat Mar 09, 2019 3:32 pm

It is a good thing if you get the geometry right from the beginning,
the results are:
Correct action at 12th and string height at the bridge.
This makes things to go very smooth in the next builds.
But if not (I did not in my first build),
you can correct things by tapering the fretboard,
using taller frets, higher bridge etc.
And then adjust the solera a bit to your next build (I did so).
It sounds that you understand how precise this has to be and therefor
risk that you get centimeters action or the strings resting on the fretboard
is minimal.
Good luck.

Vesa
Vesa Kuokkanen

Antonio Marin nr. 813 1995 (Bouchet)
Vesa Kuokkanen 2016

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sbooder
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Re: Making my first solera.

Post by sbooder » Sat Mar 09, 2019 4:33 pm

Well, turned up today at Bricomarché to collect the one and only piece of (22mm) MDF they had (which I had reserved) and it was sold! MDF is so hard to find in France, I have decided to change to plywood. I know it will be harder to get the radius into the board but if time taken; I am guessing it will be a more stable build?

Off to Castorama tomorrow, and if it takes buying two sheets of 10mm ply that will have to be glued, I am determined to get this done.
Kind regards,
Simon.

Matthew Masail
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Re: Making my first solera.

Post by Matthew Masail » Sat Mar 09, 2019 6:15 pm

I just built my first solera, with adjustable blocks. I used 28mm thick MDF and some aluminium window tubing to brace it with in a cross pattern, it has been dead stable, also 28mm mdf is a whole lot more stable than the thinner stuff. I can't imagine MDF is hard to get, just find a shop that makes kitchen cabinets and they should have a lot of scraps. the aluminium tubing is ideal, also easy to find at the right place. I can post a picture if you'd like. plywood would work even if it's a pain to dish... alternatively you could build with a flat top ala Hauser and a little more neck angle.

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sbooder
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Re: Making my first solera.

Post by sbooder » Sat Mar 09, 2019 6:44 pm

Matthew Masail wrote:
Sat Mar 09, 2019 6:15 pm
I just built my first solera, with adjustable blocks. I used 28mm thick MDF and some aluminium window tubing to brace it with in a cross pattern, it has been dead stable, also 28mm mdf is a whole lot more stable than the thinner stuff. I can't imagine MDF is hard to get, just find a shop that makes kitchen cabinets and they should have a lot of scraps. the aluminium tubing is ideal, also easy to find at the right place. I can post a picture if you'd like. plywood would work even if it's a pain to dish... alternatively you could build with a flat top ala Hauser and a little more neck angle.
MDF is hard to get in France. They tend to favour particle board, in fact we could not move for particle board in both Bricomarché & Bricorama, but not a sniff of MDF.
Kind regards,
Simon.

Matthew Masail
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Re: Making my first solera.

Post by Matthew Masail » Sat Mar 09, 2019 7:37 pm

sbooder wrote:
Sat Mar 09, 2019 6:44 pm
Matthew Masail wrote:
Sat Mar 09, 2019 6:15 pm
I just built my first solera, with adjustable blocks. I used 28mm thick MDF and some aluminium window tubing to brace it with in a cross pattern, it has been dead stable, also 28mm mdf is a whole lot more stable than the thinner stuff. I can't imagine MDF is hard to get, just find a shop that makes kitchen cabinets and they should have a lot of scraps. the aluminium tubing is ideal, also easy to find at the right place. I can post a picture if you'd like. plywood would work even if it's a pain to dish... alternatively you could build with a flat top ala Hauser and a little more neck angle.
MDF is hard to get in France. They tend to favour particle board, in fact we could not move for particle board in both Bricomarché & Bricorama, but not a sniff of MDF.
So wierd, it's the opposite here, MDF is everywhere.

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sbooder
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Re: Making my first solera.

Post by sbooder » Sat Mar 09, 2019 7:40 pm

Matthew Masail wrote:
Sat Mar 09, 2019 7:37 pm
sbooder wrote:
Sat Mar 09, 2019 6:44 pm
Matthew Masail wrote:
Sat Mar 09, 2019 6:15 pm
I just built my first solera, with adjustable blocks. I used 28mm thick MDF and some aluminium window tubing to brace it with in a cross pattern, it has been dead stable, also 28mm mdf is a whole lot more stable than the thinner stuff. I can't imagine MDF is hard to get, just find a shop that makes kitchen cabinets and they should have a lot of scraps. the aluminium tubing is ideal, also easy to find at the right place. I can post a picture if you'd like. plywood would work even if it's a pain to dish... alternatively you could build with a flat top ala Hauser and a little more neck angle.
MDF is hard to get in France. They tend to favour particle board, in fact we could not move for particle board in both Bricomarché & Bricorama, but not a sniff of MDF.
So wierd, it's the opposite here, MDF is everywhere.
Where is here? If the UK, I know. Being and Englishman, I remember MDF being on every BBC house makeover program in the 90s.
Kind regards,
Simon.

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geoff-bristol
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Re: Making my first solera.

Post by geoff-bristol » Sat Mar 09, 2019 9:12 pm

To understand the angles of a guitar get a large sheet of paper - and draw up full size the side-on profile as you plan to do it. You will see first hand what neck angle is all about. The variations - such as board taper - are hard to get your head around. Drawing up makes it all clear - and what effect one thing has on another.

Matthew Masail
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Re: Making my first solera.

Post by Matthew Masail » Sat Mar 09, 2019 10:03 pm

sbooder wrote:
Sat Mar 09, 2019 7:40 pm
Matthew Masail wrote:
Sat Mar 09, 2019 7:37 pm
sbooder wrote:
Sat Mar 09, 2019 6:44 pm


MDF is hard to get in France. They tend to favour particle board, in fact we could not move for particle board in both Bricomarché & Bricorama, but not a sniff of MDF.
So wierd, it's the opposite here, MDF is everywhere.
Where is here? If the UK, I know. Being and Englishman, I remember MDF being on every BBC house makeover program in the 90s.
Lol I used to watched those too with my father! I remember loving it... lol
I'm in Israel, if you can get baltic birch plywood it is very stable, I use many many sheets of it every month. if you laminate it to itself it'll make a stable platform to build on. you can cut a dome into it, it wont be fun but you only have to do it once. or check out Pablo Requena on you tube, he has a solera in which is raised the whole surface with cork instead of cutting a dome into the solera. but I don't think it would work well if you plan to have adjustable blocks.

honestly, if you add some bracing underneath, a section of laminated pine from Ikea would do a decent job too, just keep it up to 2cm thick so the bracing provides most of the stability.

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